Underreamer



Filed uly 5. 1923 Had 5 Patented May 6, 1924.

um'rso stares rA'rENT OFFICE.

FRED SWAN, OF MARIET'I'A, OHIO, ASSIGNOR '10 BBIDGEPORT MACHINE COMPANY, 01! WIGEITA, KA NSAS, A CORPORATION OF DELAWARE.

UNDEBREAMER.

Application fll ed July 3, 1923. Serial No. 040,339.

To all whom it may concern Be it known that I, FRED SWAN,

a citizen In the drawings 1 indicates'the body of the under-reamer having the central bore 2 of the United States, residing at Marietta, in \for the rod which carries the cross-bar for the county of Washington and State of Ohio, have invented certain new and useful Improvements in Underreamers, of which the following is a specification.

My invention relates to under-reamers, that is devices for reaming out or enlarging well holes drilled below casing and has for its object an improvement in the wedge of the under-reamer of U. S. patent to John C. Swan for under-reamer, No. 979,106, dated December 20, 1910, by which the underreamer of that patent will be adapted for use in wellholes of large diameter.

In the under-reamer of the patent referred to the reamer body has its lower end shaped to form a wedge and its upper portion bored out to form a spring case; the wedge is slotted at right an les to they wedge surfaces and through'this sit extends a cross-bar carrying reaming bits or cutters which slide on the faces of the wedge and are provided with means for engaging guide ways in the housings formed by the portions of the wedge which are separated by the slot.

For use in well holes of diameters commonly used at the date of the patent referred 80 to, that is up to 12 inches, the under-reamer having its wedge formed as shown and disclosed in the patent needs no change. For under-reaming well holes of diameters 12 inches and larger particularly those of 15 85 130.18" or over the length of wedge necessary if the construction shownand described in the patent is followed, is objectionable.

It is the object of my present invention to provide a construction by which the length of the wedge may be materially reduced.

With this object in view my invention consists in the construction hereinafter described and claimed. i

Referring to the drawings: e5 Fi re 1 is a central longitudinal sectional view of the lower portions of an under-reamer body embodymg mfy invention. Fig. 2 is an enlarged view 0 one side of the wedge. as Fig. 3 is a cross-sectional view on lines 3-3 of Fig. 1 showing the reaming bits or cutters in position, and

Fig. 4 is a cross-sectional view on lines f HofFigl.

third of t e reaming bits or cutters, suitably enlarged in its upper portion to form the case 3 for the spring 1n which the reaming bits or cutters are drawn up on the wedge to expanded position. 4 indicates the wedge.

The wedge 4 is tapered from its-lower end at a relatively great angle to the axial line of the under-reamer body, as indicated at 5, the'taper at this angle extending from the lower end of the wedge to the point 6. From the point 6 to the point 7 the ta er, as shown at 8 is at a'much slighter ang e and corresponds substantially to the angle of the lower portion of the face of the wedge in the Patent'No. 979,106 referred to. From the point 7 to the abutment 9 the angle of the face is substantially the same as that of the upper portion of the wedge of the patent referred to as shown at 10. The line of inclination of the face 5 if prolonged, as indicated, at 5' in Fig. 2 would cross the axial line of the under-reamer body a short dis tance below the lower end of the wedge. The line of inclination of the face 8 if pro longed, as indicated at 8 in Figure 2 would cross the axial line at a distance below the lower end of the wedge about equal to the length of the wedge from its lower end to the abutment 9.

In order to permit of the travel of the reaming bits or cutters 20 on the guide ribs 21 formed in the housings the inner face of the wedge is formed parallel with the outer face 5 as shown at 11 and is continued at the same angle to a point 12 about half way between the points 6 and 7 and from this point to the abutment 9, the inner face of the guide ribs is formed in the same angle as that of the upper portion .10. The inner face of the lon 'tudinal recess back of the guide rib is so fo rmed as to give ample clearancefor the lugs 22 of the reaming bits or cutters. For this gurpose the inner face of this recess is cut cm the lower end of the wedge to a point 13 about in line with the oint 7 on an angle to the axis of the un er-reamer body less than the angle of the face 5 and from the oint 13 to a point 14 about one the distance from point 13 to the abutment 9,-on an angle corresponding to about the angle of the face 8. From the point 14 to the abutment 9 this inner face 15 out on substantially the angle of the up per ortion 10.

' at I claim is:

5 An under-reamer body having a wedge shaped ortion having guide ribs extending longitu inally thereof adapted to receive and sup ort reaming bits, having its lower ortion ormed at arelatively great angle to 10 t elongitudinal axis of the body and its upper memes portion formed at a'relatively slight angle to said longitudinal axis and having a portion intermediate the lower and upper portions formed at an angle to said longitudinal axis intermediate that of the angles of said lower and upper portions.

In testimony whereof I hereunto aflix my signature.

FRED SWAN. I i 

